Although the invention is designed to alleviate pain in any area of the body by the application of salts and concentration of heat at the affected area, it is particularly useful where the area can be surrounded and have heat focused upon it. For example, limb joints such as those of the knees, elbows, ankles, hands, or feet can be enclosed by an insulating sleeve arranged about an applicator to further concentrate heat internally of the sleeve where it is most effective in pain relief. Alternatively, however, heat and salt can be applied and concentrated by the applicator without the use of a surrounding sleeve on such areas as the neck, the lower back, hip or shoulder. In such circumstances, a covering towel or cloth may serve as a heat retainer of sorts, although somewhat less effectively than the surrounding sleeve.
Muscle and joint pain may be caused by any one or more of numerous conditions, but probably the most common source of such pain is arthritis. In fact, it has been estimated that as much as a third of the population of the United States is affected to some degree by arthritis. The symptoms are usually pain caused by inflamed or aching joints or muscles. One prescription for the relief of such pain is the application of heat. Dry heat application is sometimes used, but often heat is applied by immersing the affected joint in warm water in which salts are dissolved. Alternatively, warm cloths moistened by a salt solution have been applied to affected areas in an effort to alleviate pain. These efforts have met with some success, but the need for improvements has been noted, particularly in avoiding the discomfort of wetness, especially when applicators become cooled.